The present invention is directed to novel 7-heterocyclyl quinoline and thieno[2,3-b]pyridine derivatives, pharmaceutical compositions containing them and their use in the treatment of disorders and conditions associated with gonadotropin releasing hormone (GnRH). The compounds of the invention are antagonists of GnRH, useful in the treatment of infertility, prostate cancer, benign prostate hyperplasia (BPH), and useful as contraceptives.
Gonadotropin-releasing hormone (GnRH), also referred to as luteinizing hormone-releasing hormone (LHRH) is a linear decapeptide amide, pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2, originally isolated from porcine (Matsuo, H., et. al., Biochem. Biophys. Res. Commun. 1972, 43, 1334-1339) and ovine (Burgus, R., et. al., PNAS, USA, 1972, 69, 278-282) sources. GnRH plays a key role in the reproductive system. The hormone is released from the hypothalamus and acts on the pituitary gland to stimulate the biosynthesis and secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). LH released from the pituitary gland is primarily responsible for the regulation of gonadal steroid production in both males and females, whereas FSH regulates spermatogenesis in males and follicular development in females.
GnRH-based therapies using peptidic GnRH agonists and antagonists have been shown effective in the treatment of conditions associated with LH/FSH release, such as endometriosis, uterine fibroids, polycystic ovarian disease, precocious puberty and some gonadal steroid-dependent neoplasia, particularly prostate cancer, breast cancer and ovarian cancer. GnRH agonists and antagonists are also useful in the treatment of fertility and as a contraceptive in both males and females.
Although the compounds of the present invention are useful primarily for the treatment of disorders and conditions associated with the reproductive system, they may also be useful for the treatment of other GnRH mediated disorders and conditions including pituitary gonadotrope adenomas, sleep disorders, benign prostate hyperplasia, and prostate cancer.
Peptide-like GnRH antagonists are known, for example, derivatives of straight-chain peptides (U.S. Pat. Nos. 5,140,009 and 517,835), cyclic hexapeptide derivatives (Japanese Patent Application Laid-open No. 61(1986)-191698), and bicyclic peptide derivatives (J. Med. Chem. 1993, 36, 3265). However, due to a lack of bioavailability, these compounds are limited to intravenous and subcutaneous administration.
Recently, small molecule, non-peptide GnRH antagonists have been disclosed. Kato, et al., in EP0679642 disclose isochroman derivatives which have gonadotropin releasing hormone receptor antagonizing activity, as well as calcium-antagonizing and monoamine-uptake inhibiting activities.
Ohkawa et al., in WO96/38438 disclose tricyclic diazepine derivatives which have gonadotropin releasing hormone receptor antagonist activity.
Ohkawa et al., in WO95/29900 disclose condensed heterocyclic compounds which have GnRH receptor antagonistic action and/or an action of improving sleep disturbances.
Furuya et al., in WO97/14682 disclose quinolone derivatives as GnRH antagonists, useful as prophylactic or therapeutic agents for the prevention or treatment of sex hormone dependent disease.
Goulet et al., in WO97/44037 and in WO97/44041, Goulet et al., in WO97/44321 and Goulet et al., in WO97/44339 disclose non-peptide antagonists of GnRH useful for the treatment of a variety of sex-hormone related conditions in men and women. Goulet et al., in WO97/21703 and in WO97/21707 disclose non-peptide antagonists of GnRH useful for the treatment of a variety of sex-hormone related conditions in men and women.
Furuya et al., in WO95/28405 disclose bicyclic thiophene derivatives with gonadotropin releasing hormone receptor antagonizing activity. Furuya et al., in WO97/41126 disclose 4,7-dihydro-4-oxothieno[2,3-b]pyridine derivatives having GnRH antagonistic activity. Furuya, et al., in WO97/14697 disclose thieno[2,3-b]pyridine derivatives as GnRH antagonists.
The present invention is directed to a compound of formula (I) or (II): 
wherein
L1 is selected from the group consisting of CH2, CH(CH3) and C(CH3)2;
R1 and R2are independently selected from the group consisting of alkyl, cycloalkyl, aryl, aralkyl, heteroaryl and heterocycloalkyl; wherein the aryl, heteroaryl or heterocycloalkyl group is optionally substituted with one or more substituents independently selected from halogen, alkyl, alkoxy, nitro, NH2, NH(alkyl), N(alkyl)2, xe2x80x94C(O)-alkyl, xe2x80x94C(O)-aryl or xe2x80x94C(O)-cycloalkyl;
X is selected from the group consisting of O, S and NRA; where RA is selected from hydrogen, alkyl, aryl or aralkyl;
R4 is selected from the group consisting of xe2x80x94C(O)xe2x80x94RB, xe2x80x94C(O)Oxe2x80x94RB, xe2x80x94C(O)NH2, xe2x80x94C(O)xe2x80x94NHB, xe2x80x94C(O)xe2x80x94N(RB)2, and xe2x80x94C(O)NHNH2;
wherein RB is selected from the group consisting of alkyl, aryl, aralkyl and cycloalkyl;
alternatively X is N and is taken together with R4 to form a ring structure selected from the group consisting of pyrazolyl, dihydropyrazolyl, isoxazolinyl and dihydropyrimidinyl; wherein the ring structure is optionally substituted with one or more RC;
wherein each RC is independently selected from the group consisting of oxo, alkyl, alkoxy, amino, alkylamino, dialkylamino, aryl, xe2x80x94O-aryl, aralkyl and xe2x80x94O-aralkyl;
L2 is selected from the group consisting of alkyl;
R3 is selected from the group consisting of alkyl, cycloalkyl, aryl, aralkyl, heteroaryl and heterocycloalkyl; wherein the cycloalkyl, aryl, aralkyl, heteroaryl or heterocycloalkyl group is optionally substituted with one or more substituents independently selected from halogen, alkyl, alkoxy, nitro, NH2, NH(alkyl), N(alkyl)2, cyano or sulfonamido;
R5 is selected from the group consisting of halogen, cycloalkyl, aryl, aralkyl, heteroaryl or heterocycloalkyl; wherein the cycloalkyl, aryl, aralkyl, heteroaryl or heterocycloalkyl group is optionally substituted with one or more substituents selected from halogen, alkyl, alkoxy, nitro, NH2, NH(alkyl), N(alkyl)2, cyano or sulfonamido;
provided that when X is O, then R5 is selected from the group consisting of heteroaryl or heterocycloalkyl; wherein the heteroaryl or heterocycloalkyl group is optionally substituted with one or more substituents selected from halogen, alkyl, alkoxy, nitro, NH2, NH(alkyl), N(alkyl)2, cyano or sulfonamido;
and pharmaceutically acceptable salts, esters and pro-drugs thereof.
In an aspect of the present invention is the compound 4,7-dihydro-2-(4-methoxyphenyl)-7-[(2-methoxyphenyl) methyl]-3-[[methyl(phenylmethyl)amino]methyl]-4-oxo-thieno[2,3-b]pyridine-5-carboxylic acid hydrazide, and pharmaceutically acceptable salts, esters and prodrugs thereof.
Illustrative of the invention is a pharmaceutical composition comprising a pharmaceutically acceptable carrier and any of the compounds described above. An illustration of the invention is a pharmaceutical composition made by mixing any of the compounds described above and a pharmaceutically acceptable carrier. Illustrating the invention is a process for making a pharmaceutical composition comprising mixing any of the compounds described above and a pharmaceutically acceptable carrier.
Exemplifying the invention are methods of treating disorders or diseases which respond to antagonism of GnRH, in a subject in need thereof comprising administering to the subject a therapeutically effective amount of any of the compounds or pharmaceutical compositions described above.
An example of the invention is a method for treating infertility, prostate cancer or benign prostate hyperplasia (BPH), in a subject in need thereof comprising administering to the subject an effective amount of any of the compounds or pharmaceutical compositions described above.
A further example of the invention is a method of female or male contraception, in a subject in need thereof comprising administering to the subject a therapeutically effective amount of any of the compounds or pharmaceutical compositions described above.
Yet another example of the invention is the use of any of the compounds described herein in the preparation of a medicament for treating: (a) infertility, (b) prostate cancer, (c) benign prostate hyperplasia (BPH) or for (d) contraception, in a subject in need thereof.
The present invention is directed to a compound of formula (I) or (II): 
wherein L1, R1, R2, X, R4, L2, R3 and R5 are as previously described, useful in the treatment of disorders or diseases which respond to antagonism of the GnRH such as infertility, prostate cancer, benign prostate hyperplasia (BPH), and the like. The compounds of the present invention are further useful as contraceptives.
In one embodiment of the present invention are compounds of the formula (I) wherein
L1 is CH2;
R1 and R2 are independently selected from the group consisting of lower alkyl, cycloalkyl, aryl, aralkyl, heteroaryl and heterocycloalkyl; wherein the aryl, aralkyl, heteroaryl or heterocycloalkyl may be optionally substituted with one to two substituents independently selected from halogen, lower alkyl, lower alkoxy, nitro, NH2, NH(lower alkyl) or N(lower alkyl)2;
X is O;
R4 is selected from the group consisting of xe2x80x94C(O)O-alkyl, xe2x80x94C(O)O-aryl and xe2x80x94C(O)NHNH2;
alternatively X is N and is taken together with R4 to form a ring structure selected from the group consisting of pyrazolyl, pyrazolinyl, dihydropyridyl and dihydropyrimidyl, wherein the ring structure is optionally substituted with one to two substituents independently selected from oxo, lower alkyl, lower alkoxy, aryl, xe2x80x94O-aryl, aralkyl or xe2x80x94O-aralkyl;
L2 is selected from the group consisting of lower alkyl;
R3 is selected from the group consisting of aryl; wherein the aryl group is optionally substituted with one to two substituents independently selected from halogen, lower alkyl, lower alkoxy, nitro, NH2, NH(lower alkyl), N(lower alkyl)2, cyano or sulfonamido;
R5 is selected from the group consisting of halogen, cycloalkyl, aryl, aralkyl, heteroaryl, and heterocycloalkyl wherein the cycloalkyl, aryl, aralkyl, heteroaryl or heterocycloalkyl is optionally substituted with one to two substituents independently selected from halogen, lower alkyl, lower alkoxy, nitro, NH2, NH(lower alkyl), N(lower alkyl)2, cyano or sulfonamido;
provided that when X is O, then R5 is selected from the group consisting of heteroaryl or heterocycloalkyl; wherein the heteroaryl or heterocyloalkyl group is optionally substituted with one to two substituents selected from halogen, lower alkyl, lower alkoxy, nitro, NH2, NH(lower alkyl), N(lower alkyl)2, cyano or sulfonamido;
and pharmaceutically acceptable salts, esters and pro-drugs thereof.
In another embodiment of the present invention are compounds of the formula (I) or (II) wherein X is S and R5 is selected from the group consisting of heteroaryl or heterocycloalkyl; wherein the heteroaryl or heterocycloalkyl group is optionally substituted with one or more substituents selected from halogen, alkyl, alkoxy, nitro, NH2, NH(alkyl), N(alkyl)2, cyano or sulfonamido;
In a further embodiment of the present invention are compounds of the formula (I) or (II) wherein X is NRA or alternatively X is N and is taken together with R4 to form a ring structure selected from the group consisting of pyrazolyl, dihydropyrazolyl, isoxazolinyl and dihydropyrimidinyl; wherein the ring structure is optionally substituted with one or more RC, wherein RC is as defined above.
In a particularly preferred embodiment of the present invention are compounds of the formula (I) and (II) as listed in Tables 1 and 2.
As used herein, xe2x80x9chalogenxe2x80x9d shall mean chlorine, bromine, fluorine and iodine.
As used herein, the term xe2x80x9calkylxe2x80x9d whether used alone or as part of a substituent group, includes straight and branched chains comprising one to ten carbon atoms. For example, alkyl radicals include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, pentyl and the like. Unless otherwise noted, xe2x80x9clowerxe2x80x9d when used with alkyl means a carbon chain composition of 1-6 carbon atoms.
As used herein, unless otherwise noted, xe2x80x9calkoxyxe2x80x9d shall denote an oxygen ether radical of the above described straight or branched chain alkyl groups. For example, methoxy, ethoxy, n-propoxy, sec-butoxy, t-butoxy, n-hexyloxy and the like. Unless otherwise noted, xe2x80x9clowerxe2x80x9d when used with alkoxy means an oxygen ether radical of the above described straight or branched carbon chain alkyl group wherein the alkyl is of 1-6 carbon atoms.
As used herein, unless otherwise noted, xe2x80x9carylxe2x80x9d shall refer to carbocyclic aromatic groups such as phenyl, naphthyl, and the like.
As used herein, unless otherwise noted, xe2x80x9caralkylxe2x80x9d shall mean any lower alkyl group substituted with an aryl group such as phenyl, naphthyl and the like. For example, benzyl, phenylethyl, phenylpropyl, naphthylmethyl, and the like.
As used herein, unless otherwise noted, xe2x80x9ccycloalkylxe2x80x9d shall mean any three to eight membered, monocyclic, saturated, carbocyclic ring structure including cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cylcooctyl.
As used herein, unless otherwise noted, xe2x80x9cheteroarylxe2x80x9d shall denote any five or six membered monocyclic aromatic ring structure containing at least one heteroatom selected from the group consisting of O, N and S, optionally containing one to three additional heteroatoms independently selected from the group consisting of O, N and S; or a nine or ten membered bicyclic aromatic ring structure containing at least one heteroatom selected from the group consisting of O, N and S, optionally containing one to four additional heteroatoms independently selected from the group consisting of O, N and S. The heteroaryl group may be attached at any heteroatom or carbon atom of the ring such that the result is a stable structure.
Examples of suitable heteroaryl groups include, but are not limited to, pyrrolyl, furyl, thienyl, oxazolyl, imidazolyl, purazolyl, isoxazolyl, isothiazolyl, triazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, pyranyl, furazanyl, indolizinyl, indolyl, isoindolinyl, indazolyl, benzofuryl, benzothienyl, benzimidazolyl, benzthiazolyl, purinyl, quinolizinyl, quinolinyl, isoquinolinyl, isothiazolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, pteridinyl, and the like.
As used herein, the term xe2x80x9cheterocycloalkylxe2x80x9d shall denote any five to seven membered monocyclic, saturated, partially unsaturated or partially aromatic ring structure containing at least one heteroatom selected from the group consisting of O, N and S, optionally containing one to three additional heteroatoms independently selected from the group consisting of O, N and S; or a nine to ten membered saturated, partially unsaturated or partially aromatic bicyclic ring system containing at least one heteroatom selected from the group consisting of O, N and S, optionally containing one to four additional heteroatoms independently selected from the group consisting of O, N and S. The heterocycloalkyl group may be attached at any heteroatom or carbon atom of the ring such that the result is a stable structure.
Examples of suitable heterocycloalkyl groups include, but are not limited to, pyrrolinyl, pyrrolidinyl, dioxalanyl, imidazolinyl, imidazolidinyl, pyrazolinyl, pyrazolidinyl, piperidinyl, dioxanyl, morpholinyl, dithianyl, thiomorpholinyl, piperazinyl, trithianyl, indolinyl, chromenyl, 3,4-methylenedioxyphenyl and 2,3-dihydrobenzofuryl and the like.
When a particular group is xe2x80x9csubstitutedxe2x80x9d (e.g., cycloalkyl, aryl, aralkyl, heterocycloalkyl, heteroaryl), that group may have one or more substituents, preferably from one to five substituents, more preferably from one to three substituents, most preferably from one to two substituents, independently selected from the list of substituents.
With reference to substituents, the term xe2x80x9cindependentlyxe2x80x9d means that when more than one of such substituents is possible, such substituents may be the same or different from each other.
Under standard nomenclature used throughout this disclosure, the terminal portion of the designated side chain is described first, followed by the adjacent functionality toward the point of attachment. Thus, for example, a xe2x80x9cphenylalkylaminocarbonylalkylxe2x80x9d substituent refers to a group of the formula 
Names for chemical entities of the present invention may be generated using nomenclature rules known in the art or may alternatively be generated using commercial chemical naming software, for example ACD/Index Name (Advanced Chemistry Development, Inc., Toronto, Ontario)
For use in medicine, the salts of the compounds of this invention refer to non-toxic xe2x80x9cpharmaceutically acceptable salts.xe2x80x9d Other salts may, however, be useful in the preparation of compounds according to this invention or of their pharmaceutically acceptable salts. Suitable pharmaceutically acceptable salts of the compounds include acid addition salts which may, for example, be formed by mixing a solution of the compound with a solution of a pharmaceutically acceptable acid such as hydrochloric acid, sulfuric acid, fumaric acid, maleic acid, succinic acid, acetic acid, benzoic acid, citric acid, tartaric acid, carbonic acid or phosphoric acid. Furthermore, where the compounds of the invention carry an acidic moiety, suitable pharmaceutically acceptable salts thereof may include alkali metal salts, e.g., sodium or potassium salts; alkaline earth metal salts, e.g., calcium or magnesium salts; and salts formed with suitable organic ligands, e.g., quaternary ammonium salts. Thus, representative pharmaceutically acceptable salts include the following:
acetate, benzenesulfonate, benzoate, bicarbonate, bisulfate, bitartrate, borate, bromide, calcium edetate, camsylate, carbonate, chloride, clavulanate, citrate, dihydrochloride, edetate, edisylate, estolate, esylate, fumarate, gluceptate, gluconate, glutamate, glycollylarsanilate, hexylresorcinate, hydrabamine, hydrobromide, hydrochloride, hydroxynaphthoate, iodide, isothionate, lactate, lactobionate, laurate, malate, maleate, mandelate, mesylate, methylbromide, methyinitrate, methylsulfate, mucate, napsylate, nitrate, N-methylglucamine ammonium salt, oleate, pamoate (embonate), palmitate, pantothenate, phosphate/diphosphate, polygalacturonate, salicylate, stearate, sulfate, subacetate, succinate, tannate, tartrate, teoclate, tosylate, triethiodide and valerate.
The present invention includes within its scope prodrugs of the compounds of this invention. In general, such prodrugs will be functional derivatives of the compounds which are readily convertible in vivo into the required compound. Thus, in the methods of treatment of the present invention, the term xe2x80x9cadministeringxe2x80x9d shall encompass the treatment of the various disorders described with the compound specifically disclosed or with a compound which may not be specifically disclosed, but which converts to the specified compound in vivo after administration to the patient. Conventional procedures for the selection and preparation of suitable prodrug derivatives are described, for example, in xe2x80x9cDesign of Prodrugsxe2x80x9d, ed. H. Bundgaard, Elsevier, 1985.
Where the compounds according to this invention have at least one chiral center, they may accordingly exist as enantiomers. Where the compounds possess two or more chiral centers, they may additionally exist as diastereomers. It is to be understood that all such isomers and mixtures thereof are encompassed within the scope of the present invention. Furthermore, some of the crystalline forms for the compounds may exist as polymorphs and as such are intended to be included in the present invention. In addition, some of the compounds may form solvates with water (i.e., hydrates) or common organic solvents, and such solvates are also intended to be encompassed within the scope of this invention.
The term xe2x80x9csubjectxe2x80x9d as used herein, refers to an animal, preferably a mammal, most preferably a human, who has been the object of treatment, observation or experiment.
The term xe2x80x9ctherapeutically effective amountxe2x80x9d as used herein, means that amount of active compound or pharmaceutical agent that elicits the biological or medicinal response in a tissue system, animal or human that is being sought by a researcher, veterinarian, medical doctor or other clinician, which includes alleviation of the symptoms of the disease or disorder being treated.
As used herein, the term xe2x80x9ccompositionxe2x80x9d is intended to encompass a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from combinations of the specified ingredients in the specified amounts.
Abbreviations used in the specification, particularly the Schemes and Examples, are as follows:
xcex1MEM=Minimum Essential Medium
DCM=Dichloromethane
DIPEA=Diisopropylethylamine
DMF=N,N-Dimethylformamide
DME=Dimethoxyethane
DMSO=Dimethylsulfoxide
Et3N=Triethylamine
EtOAc=Ethyl Acetate
LHMDS=Lithium hexamethyldisilazide
MeOH=Methanol
NBS=1-bromo-2,5-pyrrolidinedione
Ph=Phenyl
RT or rt=Room temperature
TEA=Triethylamine
THF=Tetrahydrofuran
Compounds of the general formula (I) wherein X is O, may be prepared according to the process outlined in Scheme 1. 
More particularly, a compound of formula (III), a known compound or compound prepared by known methods, wherein Q is bromo or iodo, is reacted with a suitably substituted compound of formula (IV), in the presence of a base such as potassium carbonate, TEA, NaOH, NaH, DIPEA, and the like, in an organic solvent such as THF, DMF, DCM, and the like, to yield the corresponding compound of formula (V).
The compound of formula (V) is reacted with a brominating agent such as 70% NBS, and the like, in an organic solvent such as THF, DMF, DCM, and the like, to yield the corresponding compound of formula (VI).
The compound of formula (VI) is reacted with a suitably substituted amine of formula (VII), in the presence of a base such as TEA, DIPEA, and the like, in an organic solvent such as THF, DMF, and the like, to yield the corresponding compound of formula (VIII).
The compound of formula (VIII) is reacted with a suitably substituted boronic acid of formula (IX), in the presence of a catalyst such as palladium tetrakis(triphenylphosphine) (Pd(PPh3)4), and the like, in the presence of a base such as NaCO3, NaOH, and the like, in an organic solvent such as THF, DMF, dioxane, and the like, optionally in a mixture with water, to yield the corresponding compound of formula (Ia).
Compounds of formula (I) wherein X is S may be prepared according to the process outlined in Scheme 2. 
Specifically, a suitably substituted compound of formula (Ia), prepared as in Scheme 1, is reacted with a sulfonating agent such as P4S10, Lawesson""s reagent, and the like, in an organic solvent such as pyridine, toluene, xylene, and the like, at an elevated temperature in the range of about 60-140xc2x0 C., to yield the corresponding compound of formula (Ib).
Compounds of formula (I) wherein X is N and is taken together with R4 to form 
wherein RD is selected from the group consisting of alkyl, aryl and aralkyl, may be prepared according to the process outlined in Scheme 3. 
More particularly, a suitably substituted compound of formula (Ib), prepared as in Scheme 2, is reacted with a compound of formula (X), in an organic solvent such as DMF, DMSO, and the like, at an elevated temperature in the range of about 80-110xc2x0C., to yield the corresponding compound of formula (Ic).
The compound of formula (Ic) is optionally further reacted with a compound of formula (XI), wherein RD is selected from the group consisting of alkyl, aryl and aralkyl, in the presence of a strong base such as LHMDS, NaH, potassium t-butoxide, and the like, to yield the corresponding compound of formula (Id).
Alternatively, the compound of formula (Ic) may be further reacted according to known methods to introduce one or more substituents on the pyrazolyl group.
Compounds of formula (I) wherein X is NRA may be prepared according to the process outlined in Scheme 4. 
More particularly, a suitably substituted compound of formula (Ib), prepared as in Scheme 2, is reacted with a suitably substituted amine of formula (XII), in an organic solvent such as DMF, DMSO, and the like, preferably at an elevated temperature in the range of about 60-120xc2x0 C., to yield the corresponding compound of formula (Ie).
Compounds of formula (I) wherein X is N and is taken together with R4 to form a ring structure selected from the group consisting of dihydropyrazolyl, isoxazolinyl and dihydropyrimidinyl may be prepared by methods known to those skilled in the art.
For example, compounds of formula (I) wherein X is N and is taken together with R4 to form dihydropyrazolyl 
may be prepared by reacting a suitably substituted compound of formula (Ia), wherein X is O and R4 is an ester of the formula xe2x80x94CO2RB, prepared as in Scheme 1, with a suitable reducing agent, to yield the corresponding compound wherein R4 is an aldehyde of the formula xe2x80x94C(O)H, subsequently reacting the R4 aldehyde with benzylcarbazate to yield the corresponding compound wherein R4 is hydrazone (xe2x80x94CHNNHxe2x80x94C(O)O-benzyl), reducing the R4 hydrazone with hydrogen gas, in the presence of a catalyst such as palladium hydroxide, to yield the corresponding compound wherein R4 is hydrazine (xe2x80x94CH2NHNH2), and then treating the R4 hydrazine with a dehydration reagent such as P2O5, at an elevated temperature to yield the corresponding dihydropyrazole substituted compound of formula (I).
Compounds of formula (I) wherein X is N and is taken together with R4 to form isoxazolinyl 
may be prepared by subjecting a suitably substituted compound of formula (Ia), wherein X is O and R4 is an ester of the formula xe2x80x94CO2RB, prepared as in Scheme 1, to saponification to convert the R4 ester group to the corresponding carboxy group (xe2x80x94CO2H) and then treating the R4 carboxy group with a suitable reducing agent, to yield the corresponding compound wherein R4 is an alcohol of the formula xe2x80x94CH2OH, converting the X is O carbonyl group to the corresponding X is S thiocarbonyl group, converting the thiocarbonyl group to the corresponding hydroxyamine where X is Nxe2x80x94OH, and then affecting ring closure of the X hydroxyamine and R4 alcohol with a dehydrating agent such as P2O5, at an elevated temperature to yield the corresponding isoxazolinyl substituted compound of formula (I).
Compounds of formula (I) wherein X is N and is taken together with R4 to form dihydropyrimidinyl 
or oxo-substituted dihydropyrimidinyl 
may be prepared by reacting a suitably substituted compound of formula (Ia), wherein R4 is an ester of the formula xe2x80x94CO2RB, prepared as in Scheme 1, with urea, thiourea, guanidine or a suitably subtituted alkyl or aryl amidine, in an organic solvent, at an elevated temperature to yield the 
substituted compound of formula (I). The oxo-substituted dihydropyrimidinyl substituted compound of formula (I) may be further optionally, alkylated according to the process described in Scheme 3, to yield the corresponding dihydropyrimidinyl substituted compound of formula (I). Similarly, the thio- or imino-substituted dihydropyrimidinyl substituted compound of formula (I) may be further, optionally reacted according to known methods to displace the thio group (xe2x95x90S) or modify the imino group (xe2x95x90NH), respectively.
Compounds of formula (II), wherein R4 is xe2x80x94C(O)Oxe2x80x94R6, X is S or X is N and is taken together with R4 to form 
may be prepared according to the process outlined in Scheme 5. 
More particularly, a compound of formula (X), a known compound or compound prepared by known methods, is reacted with a sulfonating agent such as P4S10, Lawesson""s Reagent, and the like, in the presence of an organic base such as pyridine, TEA, Hxc3xcnig""s base (DIEA), and the like, at an elevated temperature in the range of about 60-120xc2x0 C., preferably at about reflux temperature, to yield the corresponding compound of formula (IIa).
The compound of formula (IIa) may be optionally further reacted with H2Nxe2x80x94NH2, in an organic solvent such as DMF, DMSO, and the like, at an elevated temperature in the range of about 80-110xc2x0 C., to yield the corresponding compound of formula (IIb).
The compound of formula (IIb) may be further, optionally reacted according to known methods to introduce one or more substituents on the pyrazolyl group.
Compounds of formula (II) wherein X is N and taken together with R4 to form a ring selected from the group consisting of dihydropyrazolyl, isoxazolinyl and dihydropyrimidinyl, may be similarly prepared according to the processes described above, with appropriate substitution of a compound of formula (X) for the compound of formula (Ia).
Compounds of formula (II) wherein X is selected from the group consisting of O, S and NRA, may be prepared from the corresponding compound of formula (X), by methods known to those skilled in the art.
For example, compounds of formula (II) wherein X is O and R4 is other than xe2x80x94C(O)OR6 may be prepared by converting the R4 ester group on a suitably substituted compound of formula (X) to the corresponding R4 carboxy group and then using known quinolone chemistry to convert the R4 carboxy group to the desired R4 functionality.
Compounds of formula (II) wherein X is S and R4 is other than xe2x80x94C(O)OR6, may similarly be prepared by converting the xe2x80x94C(O)OR6 ester on the compound of formula (X) to the desired R4 group as described above and then converting the X is O, (carbonyl group) to the corresponding X is S (thiocarbonyl group) by reacting with a sulfonating agent, as described in Scheme 5.
Compounds of formula (II) wherein X is NRA and R4 is other than xe2x80x94C(O)OR6, may similarly be prepared by converting the xe2x80x94C(O)OR6 ester on the compound of formula (X) to the desired R4 group as described above and then converting the X is O (carbonyl group) to the corresponding X is NRA (amine group) by reacting with a suitably substituted amine, as described in Scheme 4.